/*
 Copyright  2002-2007 MySQL AB, 2008-2010 Sun Microsystems
 All rights reserved. Use is subject to license terms.

  The MySQL Connector/J is licensed under the terms of the GPL,
  like most MySQL Connectors. There are special exceptions to the
  terms and conditions of the GPL as it is applied to this software,
  see the FLOSS License Exception available on mysql.com.

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; version 2 of the
  License.

  This program is distributed in the hope that it will be useful,  
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  02110-1301 USA

 */

package com.mysql.jdbc;

import java.io.InputStream;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.sql.NClob;
import java.sql.RowId;
import java.sql.SQLException;
import java.sql.SQLXML;

import com.mysql.jdbc.Connection;
import com.mysql.jdbc.Field;
import com.mysql.jdbc.NotUpdatable;
import com.mysql.jdbc.ResultSetImpl;
import com.mysql.jdbc.RowData;
import com.mysql.jdbc.SQLError;
import com.mysql.jdbc.Statement;


public class JDBC4ResultSet extends ResultSetImpl {

	public JDBC4ResultSet(long updateCount, long updateID, 
			MySQLConnection conn, StatementImpl creatorStmt) {
		super(updateCount, updateID, conn, creatorStmt);
	}
	
	public JDBC4ResultSet(String catalog, Field[] fields, RowData tuples,
			MySQLConnection conn, StatementImpl creatorStmt) throws SQLException {
		super(catalog, fields, tuples, conn, creatorStmt);
	}
	
	/**
	 * JDBC 4.0
	 * 
	 * <p>
	 * Get the value of a column in the current row as a java.io.Reader.
	 * </p>
	 * 
	 * @param columnIndex
	 *            the column to get the value from
	 * 
	 * @return the value in the column as a java.io.Reader.
	 * 
	 * @throws SQLException
	 *             if an error occurs
	 */
	public Reader getNCharacterStream(int columnIndex) throws SQLException {
		checkColumnBounds(columnIndex);
		
		String fieldEncoding = this.fields[columnIndex - 1].getCharacterSet();
		if (fieldEncoding == null || !fieldEncoding.equals("UTF-8")) {
			throw new SQLException(
					"Can not call getNCharacterStream() when field's charset isn't UTF-8");
		}
		return getCharacterStream(columnIndex);
	}

	/**
	 * JDBC 4.0
	 * 
	 * <p>
	 * Get the value of a column in the current row as a java.io.Reader.
	 * </p>
	 * 
	 * @param columnName
	 *            the column name to retrieve the value from
	 * 
	 * @return the value as a java.io.Reader
	 * 
	 * @throws SQLException
	 *             if an error occurs
	 */
	public Reader getNCharacterStream(String columnName) throws SQLException {
		return getNCharacterStream(findColumn(columnName));
	}

	/**
	 * JDBC 4.0 Get a NCLOB column.
	 * 
	 * @param i
	 *            the first column is 1, the second is 2, ...
	 * 
	 * @return an object representing a NCLOB
	 * 
	 * @throws SQLException
	 *             if an error occurs
	 */
	public NClob getNClob(int columnIndex) throws SQLException {
		checkColumnBounds(columnIndex);
		
		String fieldEncoding = this.fields[columnIndex - 1].getCharacterSet();
		if (fieldEncoding == null || !fieldEncoding.equals("UTF-8")) {
			throw new SQLException(
					"Can not call getNClob() when field's charset isn't UTF-8");
		}
		if (!this.isBinaryEncoded) {
			String asString = getStringForNClob(columnIndex);

			if (asString == null) {
				return null;
			}

			return new com.mysql.jdbc.JDBC4NClob(asString, getExceptionInterceptor());
		}

		return getNativeNClob(columnIndex);
	}

	/**
	 * JDBC 4.0 Get a NCLOB column.
	 * 
	 * @param colName
	 *            the column name
	 * 
	 * @return an object representing a NCLOB
	 * 
	 * @throws SQLException
	 *             if an error occurs
	 */
	public NClob getNClob(String columnName) throws SQLException {
		return getNClob(findColumn(columnName));
	}
	
	/**
	 * JDBC 4.0 Get a NCLOB column.
	 * 
	 * @param columnIndex
	 *            the first column is 1, the second is 2, ...
	 * 
	 * @return an object representing a NCLOB
	 * 
	 * @throws SQLException
	 *             if an error occurs
	 */
	protected java.sql.NClob getNativeNClob(int columnIndex)
			throws SQLException {
		String stringVal = getStringForNClob(columnIndex);

		if (stringVal == null) {
			return null;
		}

		return getNClobFromString(stringVal, columnIndex);
	}
	
	private String getStringForNClob(int columnIndex) throws SQLException {
		String asString = null;

		String forcedEncoding = "UTF-8";

		try {
			byte[] asBytes = null;

			if (!this.isBinaryEncoded) {
				asBytes = getBytes(columnIndex);
			} else {
				asBytes = getNativeBytes(columnIndex, true);
			}

			if (asBytes != null) {
				asString = new String(asBytes, forcedEncoding);
			}
		} catch (UnsupportedEncodingException uee) {
			throw SQLError.createSQLException("Unsupported character encoding "
					+ forcedEncoding, SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
		}

		return asString;
	}
	
	private final java.sql.NClob getNClobFromString(String stringVal,
			int columnIndex) throws SQLException {
		return new com.mysql.jdbc.JDBC4NClob(stringVal, getExceptionInterceptor());
	}
	
	/**
	 * JDBC 4.0
	 * 
	 * Get the value of a column in the current row as a Java String
	 * 
	 * @param columnIndex
	 *            the first column is 1, the second is 2...
	 * 
	 * @return the column value, null for SQL NULL
	 * 
	 * @exception SQLException
	 *                if a database access error occurs
	 */
	public String getNString(int columnIndex) throws SQLException {
		checkColumnBounds(columnIndex);
		
		String fieldEncoding = this.fields[columnIndex - 1].getCharacterSet();
		if (fieldEncoding == null || !fieldEncoding.equals("UTF-8")) {
			throw new SQLException(
					"Can not call getNString() when field's charset isn't UTF-8");
		}
		return getString(columnIndex);
	}
	
	/**
	 * JDBC 4.0
	 * 
	 * The following routines simply convert the columnName into a columnIndex
	 * and then call the appropriate routine above.
	 * 
	 * @param columnName
	 *            is the SQL name of the column
	 * 
	 * @return the column value
	 * 
	 * @exception SQLException
	 *                if a database access error occurs
	 */
	public String getNString(String columnName) throws SQLException {
		return getNString(findColumn(columnName));
	}
	
	/**
	 * JDBC 4.0 Update a column with a character stream value. The updateXXX()
	 * methods are used to update column values in the current row, or the
	 * insert row. The updateXXX() methods do not update the underlying
	 * database, instead the updateRow() or insertRow() methods are called to
	 * update the database.
	 * 
	 * @param columnIndex
	 *            the first column is 1, the second is 2, ...
	 * @param x
	 *            the new column value
	 * @param length
	 *            the length of the stream
	 * 
	 * @exception SQLException
	 *                if a database-access error occurs
	 * @throws NotUpdatable
	 *             DOCUMENT ME!
	 */
	public void updateNCharacterStream(int columnIndex, Reader x, int length)
			throws SQLException {
		throw new NotUpdatable();
	}

	/**
	 * JDBC 4.0 Update a column with a character stream value. The updateXXX()
	 * methods are used to update column values in the current row, or the
	 * insert row. The updateXXX() methods do not update the underlying
	 * database, instead the updateRow() or insertRow() methods are called to
	 * update the database.
	 * 
	 * @param columnName
	 *            the name of the column
	 * @param reader
	 *            the stream to update the column with
	 * @param length
	 *            of the stream
	 * 
	 * @throws SQLException
	 *             if a database-access error occurs
	 */
	public void updateNCharacterStream(String columnName, Reader reader,
			int length) throws SQLException {
		updateNCharacterStream(findColumn(columnName), reader, length);
	}

	/**
	 * @see ResultSet#updateNClob(String, NClob)
	 */
	public void updateNClob(String columnName, NClob nClob) throws SQLException {
		updateNClob(findColumn(columnName), nClob);
	}
	
	public void updateRowId(int columnIndex, RowId x) throws SQLException {
		throw new NotUpdatable();
	}

	public void updateRowId(String columnName, RowId x) throws SQLException {
		updateRowId(findColumn(columnName), x);
	}

	public int getHoldability() throws SQLException {
		throw SQLError.notImplemented();
	}

	public RowId getRowId(int columnIndex) throws SQLException {
		throw SQLError.notImplemented();
	}

	public RowId getRowId(String columnLabel) throws SQLException {
		return getRowId(findColumn(columnLabel));
	}

	public SQLXML getSQLXML(int columnIndex) throws SQLException {
		checkColumnBounds(columnIndex);
		
		return new JDBC4MysqlSQLXML(this, columnIndex, getExceptionInterceptor());
	}

	public SQLXML getSQLXML(String columnLabel) throws SQLException {
		return getSQLXML(findColumn(columnLabel));
	}

	public synchronized boolean isClosed() throws SQLException {
		return this.isClosed;
	}

	public void updateAsciiStream(int columnIndex, InputStream x) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateAsciiStream(String columnLabel, InputStream x) throws SQLException {
		updateAsciiStream(findColumn(columnLabel), x);
		
	}

	public void updateAsciiStream(int columnIndex, InputStream x, long length) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateAsciiStream(String columnLabel, InputStream x, long length) throws SQLException {
		updateAsciiStream(findColumn(columnLabel), x, length);
	}

	public void updateBinaryStream(int columnIndex, InputStream x) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateBinaryStream(String columnLabel, InputStream x) throws SQLException {
		updateBinaryStream(findColumn(columnLabel), x);
	}

	public void updateBinaryStream(int columnIndex, InputStream x, long length) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateBinaryStream(String columnLabel, InputStream x, long length) throws SQLException {
		updateBinaryStream(findColumn(columnLabel), x, length);
	}

	public void updateBlob(int columnIndex, InputStream inputStream) throws SQLException {
		throw new NotUpdatable();
	}

	public void updateBlob(String columnLabel, InputStream inputStream) throws SQLException {
		updateBlob(findColumn(columnLabel), inputStream);
	}

	public void updateBlob(int columnIndex, InputStream inputStream, long length) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateBlob(String columnLabel, InputStream inputStream, long length) throws SQLException {
		updateBlob(findColumn(columnLabel), inputStream, length);
	}

	public void updateCharacterStream(int columnIndex, Reader x) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateCharacterStream(String columnLabel, Reader reader) throws SQLException {
		updateCharacterStream(findColumn(columnLabel), reader);
	}

	public void updateCharacterStream(int columnIndex, Reader x, long length) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateCharacterStream(String columnLabel, Reader reader, long length) throws SQLException {
		updateCharacterStream(findColumn(columnLabel), reader, length);
	}

	public void updateClob(int columnIndex, Reader reader) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateClob(String columnLabel, Reader reader) throws SQLException {
		updateClob(findColumn(columnLabel), reader);
	}

	public void updateClob(int columnIndex, Reader reader, long length) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateClob(String columnLabel, Reader reader, long length) throws SQLException {
		updateClob(findColumn(columnLabel), reader, length);
	}

	public void updateNCharacterStream(int columnIndex, Reader x) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateNCharacterStream(String columnLabel, Reader reader) throws SQLException {
		updateNCharacterStream(findColumn(columnLabel), reader);
		
	}

	public void updateNCharacterStream(int columnIndex, Reader x, long length) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateNCharacterStream(String columnLabel, Reader reader, long length) throws SQLException {
		updateNCharacterStream(findColumn(columnLabel), reader, length);
	}

	public void updateNClob(int columnIndex, NClob nClob) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateNClob(int columnIndex, Reader reader) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateNClob(String columnLabel, Reader reader) throws SQLException {
		updateNClob(findColumn(columnLabel), reader);
		
	}

	public void updateNClob(int columnIndex, Reader reader, long length) throws SQLException {
		throw new NotUpdatable();
	}

	public void updateNClob(String columnLabel, Reader reader, long length) throws SQLException {
		updateNClob(findColumn(columnLabel), reader, length);
	}

	public void updateNString(int columnIndex, String nString) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateNString(String columnLabel, String nString) throws SQLException {
		updateNString(findColumn(columnLabel), nString);
	}

	public void updateSQLXML(int columnIndex, SQLXML xmlObject) throws SQLException {
		throw new NotUpdatable();
		
	}

	public void updateSQLXML(String columnLabel, SQLXML xmlObject) throws SQLException {
		updateSQLXML(findColumn(columnLabel), xmlObject);
		
	}

	/**
     * Returns true if this either implements the interface argument or is directly or indirectly a wrapper
     * for an object that does. Returns false otherwise. If this implements the interface then return true,
     * else if this is a wrapper then return the result of recursively calling <code>isWrapperFor</code> on the wrapped
     * object. If this does not implement the interface and is not a wrapper, return false.
     * This method should be implemented as a low-cost operation compared to <code>unwrap</code> so that
     * callers can use this method to avoid expensive <code>unwrap</code> calls that may fail. If this method
     * returns true then calling <code>unwrap</code> with the same argument should succeed.
     *
     * @param interfaces a Class defining an interface.
     * @return true if this implements the interface or directly or indirectly wraps an object that does.
     * @throws java.sql.SQLException  if an error occurs while determining whether this is a wrapper
     * for an object with the given interface.
     * @since 1.6
     */
	public boolean isWrapperFor(Class<?> iface) throws SQLException {
		checkClosed();
		
		// This works for classes that aren't actually wrapping
		// anything
		return iface.isInstance(this);
	}

    /**
     * Returns an object that implements the given interface to allow access to non-standard methods,
     * or standard methods not exposed by the proxy.
     * The result may be either the object found to implement the interface or a proxy for that object.
     * If the receiver implements the interface then that is the object. If the receiver is a wrapper
     * and the wrapped object implements the interface then that is the object. Otherwise the object is
     *  the result of calling <code>unwrap</code> recursively on the wrapped object. If the receiver is not a
     * wrapper and does not implement the interface, then an <code>SQLException</code> is thrown.
     *
     * @param iface A Class defining an interface that the result must implement.
     * @return an object that implements the interface. May be a proxy for the actual implementing object.
     * @throws java.sql.SQLException If no object found that implements the interface 
     * @since 1.6
     */
    public <T> T unwrap(java.lang.Class<T> iface) throws java.sql.SQLException {
    	try {
    		// This works for classes that aren't actually wrapping
    		// anything
            return iface.cast(this);
        } catch (ClassCastException cce) {
            throw SQLError.createSQLException("Unable to unwrap to " + iface.toString(), 
            		SQLError.SQL_STATE_ILLEGAL_ARGUMENT, getExceptionInterceptor());
        }
    }
}
